You are always a laowai in China. You are correct in regard to this. Having a Chinese wife does not make you Chinese. In fact, it is likely to make an FT even more hated by the locals then they already are.

I never ever felt any unfriendliness directed towards myself and my 40 years my junior wife when we lived in China.

I have been advised that you personally are an all-right sort of bloke- well, I don't doubt it, but you must have some sort of bad attitude problem inhibiting you from getting along with the Chinese and more to the point, finding that Mrs Silverboy. Why don't you let me help you sort this problem out? Why don't you just follow my good advice and see if it works for you? You have to admit that your marriage prospects at the moment are somewhat less than hopeful?